PEORIA — A 26-year-old man who already has served prison time for threatening President Barack Obama pleaded guilty Thursday to threatening the judge who sentenced him.

Phillip R. Porter now faces up to 10 years in prison when sentenced by Chief U.S. District Judge James Shadid in September. Until then, he’ll be housed at a secure mental health facility in Chester. Porter entered his plea to mailing a threatening communication in connection with a letter he sent to Senior U.S. District Judge Joe B. McDade.

The indictment against Porter contains little information except that in May 2012 he threatened to kill McDade. A reason wasn’t given in the indictment nor were there any of the details of the threatening letter.

On Jan. 25, 2010, Porter called the Richmond, Va., office of the FBI four times. Each time, he said he planned to kill the president. A Secret Service agent went to his house, where Porter again said he was going to kill Obama.

Porter told the agent he was strongly opposed to Obama’s wartime policies and believed the president to be a liar and a manipulator. When he arrived in Washington, D.C., Porter said, he was going to stab Obama or shoot him.

Later, Porter said he never intended to carry out the threats. He said he made the calls because he was upset with his mother.

McDade sentenced him to 21 months in federal prison for those threats.

Andy Kravetz can be reached at 686-3283 or akravetz@pjstar.com. Follow him on Twitter @andykravetz.